public class Solution2 {
    public boolean IsPopOrder(int [] pushA,int [] popA) {
        
        Stack<Integer> stack = new Stack<>();
        int j = 0;
        for (int i = 0; i < pushA.length; i++) {
            stack.push(pushA[i]);
            while (j < popA.length && !stack.empty() && stack.peek().equals(popA[j])) {
                stack.pop();
                j++;
            }
        }
        return stack.empty();
    }
      
    }
